It isn't up to "us" or "we" to interpret the rules. That is the job of the USGA and R&A. They document what they feel are necessary interpretations in the Decisions, and then we make our rulings based on the Rules and Decisions. If further interpretation is needed, we apply to the ruling bodies for assistance.
In the interest of finishing a competition, we may try an interpretation in the heat of battle, but if there is a significant question, then we should immediately apply to the appropriate ruling body for an authorized procedure or interpretation.
The way I/we see this is that I/we are not interpreting the Rules but giving rulings based on Rules and course conditions. A hole made by a greenkeeper has not been scrupulously determined in the Rules so ad hoc interpretations are a must.
It seems that as well as Colin you are also missing the concept, but as with Colin I will not spend time trying to convert you as I know from previous experience that is not worth a shot.
However, I will throw in a question for you:
On a straight 394 meter long par4 there is an area in the deep rough 30 meters left from the left edge of the green partially 'ruined' by maintenance vehicles (tire marks and such) and it might be very difficult to play a ball from that area, depending on the lie the ball takes. The green is 20 meters wide and the hole is in the middle. Would you as a referee mark that area as GUR?
What if that area would be in the woods where there are sticks & stones as well as big trees, would that make a difference?
What if that hole would be 320 meters in length and the flag would be in the right side of the green?
Just curious to understand your thinking...
If the area is considered as being "in play" - that is, in an area which is otherwise mowed rough - then I would definitely mark it as GUR. It would be unfair to force some players to play from what is clearly abnormal ground. That's a no brainer.
If it is out in the trees with other problems than just the tire ruts, then no I would not. That would be giving relief from a condition which occurs naturally in untended rough on many courses.
The length of the hole makes no difference.